Defense Secretary Mark Esper will meet with senior South Korean leaders on Friday, amid a series of regional challenges ranging from tensions between Seoul and Tokyo to how much of the cost South Korea should pay for American troops stationed there.

Esper, on his first international trip since being confirmed as defense secretary, arrived in South Korea on Thursday evening amid an escalating feud between Seoul and Tokyo, both U.S. allies.

If the issue comes up in his meetings in Seoul, Esper is likely to reiterate that the two countries should reduce tensions and focus on the challenges posed by North Korea and China.

South Korea has said it was exploring all options in a bitter trade dispute with Japan, including scrapping an intelligence sharing pact.

The accord, the General Security of Military Information Agreement (GSOMIA), facilitates three-way intelligence gathering with Washington, which is crucial in fending off North Korea's nuclear and missile threats. The deal is automatically renewed annually on Aug. 24.

Esper arrived in Seoul a day after President Donald Trump said South Korea agreed to "pay a lot more" to shoulder costs required for the upkeep of 28,500 U.S. troops in South Korea and that talks are under way to discuss the issue.

But a spokesman at South Korea's foreign ministry told reporters on Thursday that the negotiations have not yet begun.

The trip comes after North Korea recently carried out a series of missile tests.

A spokeswoman at South Korea's defense ministry said on Thursday that South Korean Defense Minister Jeong Kyeong-doo and Esper will discuss a number of issues, including the security situation on the Korean peninsula, coordinate policy to foster denuclearization and lasting peace, and discuss key alliance issues.

On Tuesday, Esper said the United States would not overreact to the short-range missile launches by North Korea and would keep the door open to talks with Pyongyang. He also added that, despite complaints by North Korea, there was no plan to alter future joint military drills with Seoul.

South Korea is Esper's last stop on a trip that has also included visits to Australia, Japan and Mongolia.